Container closure



Aug. 31, 1965 G.wou1' ETAL CONTAINER CLOSURE 2- Sheets-Sheet 1 FiledApril 8, 1963 M M o a mw y W? h N I f I 4 0% W 5 MW United States Patent3,203,576 CGNTAENER CLOSURE Gerard Wont, Badlioevedorp, Hendrik Weertmanand Hans 'Fehres, Amstelveen, Netherlands, assignors, by

mesne assignments, to Inland Steel Company, Chicago,

Ill., a corporation of Delaware Filed Apr. 8, 1963, Ser. No. 271,224Claims priority, application Great Britain, Apr. 9, 1962, 13,550/62 '18Claims. (Cl. 220-39) The present invention relates generally tocontainers and, more particularly, to an improved container closureassembly and sealing arrangement therefor. In its principal aspects, theinvention is concerned with improved closure and sealing assembliessuitable for use in closing, in a fluid-tight manner, an orifice formedin a container of the type made of polyethylene or similar thermoplasticmaterial.

A major problem heretofore encountered by manufacturers and users ofcontainers suitable for transporting various commodities has been thatof providing effective closure assemblies capable of closing dischargeorifices or the like formed in such containers. This problem has been aparticularly troublesome one since often the users of such containerscontemplate storing and transporting substances which are eithercontaminated by, or tend to destroy, conventional sealing gaskets, forexample, gaskets made of rubber or the like. Because of this, there hasbeen an increasing interest in, and demand for, a closure assemblywherein an effective fluid-tight seal is created simply by tighteningdown a closure element so that mating sealing surfaces respectivelyformed on the closure element and on the portion of the containerdefining the orifice are clamped together in a fluid-tight manner.

However, such closures have created a number of problem-s, both from amanufacturing standpoint and from the standpoint of the users of thecontainers, and these problems are particularly prevalent where the sealcomprises a plastic-to-plastic fluid-tight seal. Moreover, where thecontainer is intended to permit, on an optional basis, use of ventingdiscs or reversible pouring spouts, it is desirable that the containerneck or other orifice defining portion have a flat, substantiallyradial, planar top face adapted to intimately engage a correspondingfiat face formed on the closure element, for example, a closure cap or aclosure plug. The fact that the sealing surfaces of such closureelements are not always perfectly fiat has made it difiicult to form aneffective, uniform fluid-tight seal. Additionally, where the containerneck or similar orifice defining portion is formed by molding plasticmaterial, the stresses set up therein tend to introduce furtherirregularities which detract from the effectiveness of the seal.

-In an effort to minimize the efiects of irregularities present in thesealing surfaces, it has often been necessary to carefully machine oneor both surfaces, sometimes more than a day after molding thereof, sothat the irregularities are reduced to a point where deformation of thesoft plastic material in, for example, the orifice defining portion,compensates for the tendency of the irregularities to detract from thefluid-tight seal. However, such deformaj tion requires that the closureelement be very tightly applied to the container, an operation thatoften causes permanent deformation of a portion of the closure assembly.When this occurs, the particular closure element will only vfit in or onone particular orifice defining portion that is, the closure elementsand containers are no longer interchangeable. Nor has the use of sealinggaskets or washers made of resiliently deformable material, such asrubber, provided a satisfactory solution to the problem, since the useof such material in containers which are .i,2d3 ,576 Patented Aug. 31,1965 otherwise made entirely of polyethylene or similar syntheticthermoplastic material is generally undesirable and often limits theuses to which such containers can be put.

It is a general aim of the present invention to provide an improvedcontain-er closure construction which overcomes all of the foregoingdisadvantages and which provides an effective fluid-tight .seal, yetwhich is characterized by its simplicity and reliability in operation.

Another object of the invention is to provide a fluidtight closureassembly for a container wherein at least one of the components of .theclosure assembly is shaped so as to define an integral resilient sealingsurface made of the same material as the shaped closure component. Inthis connection, it is an object of the invention to provide a novelfluid-tight closure assembly which is characterized by itseffectiveness, yet which does not require the use of foreign resilientor deformable sealing materials that may either contaminate or beattacked by the commodity within the container.

An ancillary object of the invention is to provide a novel fluid-tightclosure assembly which, while not so limited in its application, willfind especially advantageous use with containers made entirely ofthermoplastic material, and wherein .an effective, fluid-tight,plastic-to-plastic seal is obtained without the need for machining toextremely close tolerances, yet which permits the use of a permanentlyresilient material, such as rubber, at points external to the seal, andthus out of contact with the container contents, for the purpose ofpreventing excessive deformation of the resilient plastic seal.

Yet another object of the invention is the provision of a novelfluid-tight thermoplastic closure assembly which permits of ease andeconomy in manufacture, and which may be readily assembled anddisassembled.

Other objects and advantages of the invention will become apparent asthe following description proceeds, taken in conjunction with theacoompanyin g drawings, in which:

FIGURE 1 is a fragmentary vertical cross-sectional view of a portion ofa container and a closure assembly therefor embodying the features ofthe present invention, the closure assembly here shown as including ascrew-cap;

FIG. 2 is a fragmentary vertical cross-sectional view of a modified formof closure assembly also embodying the features of the presentinvention, the closure here shown as including a reversible pouringspout and with the closure cap removed;

FIG. 3 is a view similar to FIG. 2, here illustrating the closureassembly with the closure cap applied;

'FIGS. 4, 5 and 6 are fragmentary vertical cross-sectional views ofother modified forms of closure assemblies also embodying the featuresof the present invention, the assemblies here including diverse types ofclosure plugs;

FIG. 7 is an enlarged fragmentary cross-sectional view of a closureassembly similar to that shown in FIG. 1, here employing a modified capconstruction; and

FIG. 8 is a view similar to FIG. 7 of yet another modified form of theinvention.

While the invention is susceptible of various modifications andalternative forms, specific embodiments thereof have been shown by wayof example in the drawings and will herein be described in detail. Itshould be understood, however, that it is not intended to limit theinvention to the particular forms disclosed, but, on the contrary, theintention is to cover all modifications, equivalents and alternativesfalling within the spirit and scope of cludes a wall 11 made ofpolyethylene or similar thermoplastic material, which wall may be selfsupporting. However, as will be appreciated by those skilled in the art,the wall 11 may also constitute an inner or a liner accommodated in anouter or overpack (not shown). The container wall 11 is provided with anorifice 12 surrounded by an orifice defining portion in the form of aneck 14 having external screw threads 15 formed therein. The exemplaryclosure assembly includes a closure element for the orifice which in theembodiment shown in FIG. 1, takes the form of a cap 16 provided withinternal screw threads 18 of the same type and dimensions as theexternal screw threads on the neck 14, so as topermit the cap to bescrewed onto the neck in order to close and seal the container orifice.

In accordance with one of the important aspects of the presentinvention, provision is made for shaping at least one of the componentparts of the closure assembly 10 so as to form a continuous, integral,resilient sealing tongue on an external wall thereof, which tongue isformed of the same material as the shaped closure part and which defineswith the shaped closure part an external continuous groove adapted toreceive a resilient supporting ring. In the illustrative form of theinvention shown in FIG. 1, this is accomplished by forming a continuouscircumferential groove 19 in the outer surface wall of the freeextremity of the container neck 14, the groove defining an outwardlyextending resilient sealing tongue 20 :having a flat planar face 21adjacent to and engaging a sealing surface 22 of the screw cap 16.

The arrangement is such that the container neck 14 is formed with asubstantially radial planar top face 21 mating with a substantiallyradial, planar face of the cap 16. This particular shape of the neck 14permits the optional use of a venting disc (not shown), an extensiblespout (not shown), or a reversible spout of a type similar to that shown.in FIGS. 2 and 3. The cross-sectional dimentions of the groove 19 arechosen such that the Wall thickness of the sealing tongue 20 and of theannular connection thereof with the body of the container neck 14 isrelatively thin, thus rendering great flexibility to the sealing tongue.In this manner, substantial local deformations may be achieved whichpermit the sealing tongue 20 to conform with and adapt itself to anyirregularities in or on the sealing surface 22 of the screw cap 16.

While it has been found that container closures employing relativelythin resilient sealing tongues 20 are characterized by their ability toconform to substantialiy any irregularities present in the matingsealing surfaces, it has also been found that the very flexibility ofthe tongue 20 can make it difiicult to obtain, under certain conditions,at specific pressure which is sufiiciently high to insure a fluid-tightseal. Of course, the pressure may be increased by applying the closureelement with a greater force-that is, in the exemplary closure 10 shownin FIG. 1, by'screwing the cap 16 more tightly home. However, this mightserve to ultimately close the circumferential groove 19 and thereforethe advantages obtained by the provision of the groove might bedestroyed.

Accordingly, in carrying out the present invention, a resilientsupporting element 24 is positioned in the groove 19, the elementserving to support the tongue 20. As here shown, the supporting elementis in the form of a supporting ring 24 of resiliently deformablematerial which permanently retains its resiliency, such, for example, asrubber. Thus, the possibility of excessively deforming the sealingtongue 20 and partially or wholly closing the groove 19 is avoided,while at the same time, the container contents are prevented from cominginto contact with the rubber ring.

A slightly modified form of closure assembly, general y indicated at isshown in FIGURES 2 and 3 in the open and closed positions respectively.As here illustrated, the exemplary closure includes a reversible pouringspout 31 having a flange-like portion 32 resting on the top face of thecontainer neck 14. In this construction, a groove 34 is formed in theflange 32 of the spout. Moreover, the upper portion of the flange 32thatis, the sealing tongue 20in its inoperative position (FIG. 2) isinclined with respect to the sealing surface 22 as contrasted to theradial surface defined by the tongue 20 in FIG. 1. The arrangement issuch that the inclined tongue 20' is deformed and stressed when theclosure member, the cap 16', is applied (FIG. 3). It has been found thatthis shape of sealing tongue permits the elimination of a supportingring under certain conditions.

In keeping with this form of the invention, the cap 16' is provided withan annular face depending from the top wall thereof and snugly fittingin the orifice defined, in this case, by the pouring spout 31. This faceis formed by the circumferential wall of an annular rib 35 on the innersurface of the top wall of the cap 16'. Thus, the cap supports theextremity of the spout 31 in a radial direction thereby preventing itfrom being compressed inwardlyan undesirable result that might bepromoted by weakening of the flange 32 as a result of the provision ofthe groove 34.

Of course, it will be appreciated that the foregoing structuralmodifications might also be applied to the construction shown in FIG. 1wherein the groove 19 is formed in the container neck 14 proper.

Turning now to FIG. 4, a slightly modified form of closure assembly isshown here including a closure plug 36 having a flange portion 38 and ashank portion 39. The groove 19 is formed in the flange portion 38 sothat the groove 19, and the supporting ring 24 (if provided as shown inthe drawing), are well out of the way of the container contents.

Still another exemplary form of the invention is shown in FIG. 5. Ashere illustrated, the closure element is in the form of a closure plug40 having a shank 39. Here, the groove 19 is formed in the lowermostportion of the shank, thus preventing the groove 19 and supporting ring24 (if present) from being soiled or damaged by weather conditions. Ofcourse, they are also protected from other vunfavorable externalconditions. Here also, the container contents are prevented from cominginto contact with the supporting ring, since the groove 19 is facingoutwardly and the sealing tongue 20 therefore is also extendingoutwardly.

In the exemplary closure assembly shown in FIG. 6, the closure elementis also in the form of a closure p ug 41 having a flange portion 38' anda shank portion 39'. In this instance, the groove 19 is formed in thecontainer neck 14 and, in order to protect the supporting ring 24 andthe groove 19 from contamination by dirt, weather conditions or othercauses, the plug 41 is formed with a circumferential skirt 42 dependingfrom the periphery of the flange 38 and extending below the supportingring 24. Those skilled in the art will appreciate from the foregoingthat in those forms of the invention where the closure element is a capand in which the groove and the sealing tongue are formed in and on theorifice defining portion as shown in FIGS. 1-3, the same protectivefeatures are inherently provided.

Referring to FIG. 7, it will be observed that there is illustrated aclosure assembly 10 very similar to the on shown in FIG. 1. However,here the cap 16' is provided with an annular ridge 44 on its sealingsurface facing the sealing tongue 20 so that, in fact, the ridge formsthe sealing surface. Because of the small area of the top or summit ofthe ridge 44, a relatively small force exerted on the closure memberwill be capable of generating a specific pressure which is sufficientlygreat to insure a fluid-tight seal. As here illustrated, the annularface of the cap snugly fitting in the orifice is constituted by thecircumferential wall of a disc shaped projection 45 on the inner surfaceof the top wall of the cap 16'. Alternatively, the annular face may beconstituted by the circumferential wall of a recessed central portion 46of the top wall of the cap, as indicated by the dotted lines in FIG. 7.

When, as shown in FIG. 7, a supporting .ring 24 is used with a caphaving an annular ridge 44, it is important that the diameter D of thesummit of the annular n'dge 24 is greater than the diameter d of thecircle defined by the axis of the cross-section of the supporting ring.Otherwise, the supporting ring might locally or wholly be pressedoutwardly, thus perhaps giving rise to difficulties and incorrectfunctioning. Where either the closure element or the orifice definingpart are made of a thermoplastic material, one or both of these partsmay include deviations from the cylindrical shape, or they may includeinaccuracies in their dimensions. This may lead to the annular ridge 44locally or wholly engaging the sealing tongue 20 inside of thesupporting ring 24 instead of outside thereof. In order to eliminatethis possibility, the annular ridge may be provided on the surface ofthe sealing tongue 20 facing the sealing surface 22, as best indicatedat 44' in FIG. 8.

We claim as our invention:

1. In combination, a closure assembly for a container having an orificesurrounded by an orifice defining portion and a closure element for saidorifice, wherein at least one of said portion and said element has acircumferential groove formed in its outer surface wall, said groovedefining with said wall an annular, outwardly extending, at leastslightly resilient tongue adapted to sealingly engage a surface on thecooperating part of the closure assembly, and a supporting ring formedof slightly resilient material positioned in said groove.

2. A closure assembly as set forth in claim 1, further characterized inthat said orifice defining portion is a container neck, said groovebeing formed in said neck adjacent the free extremity thereof.

3. A closure assembly as set forth in claim 1, wherein said orificedefining portion is the outer extremity of a separate member projectinginto the interior of said container and having a flange-like portionresting on the container wall, said circumferential groove and sealingtongue being formed in said flange-like portion.

4. A closure assembly as set forth in claim 3, further characterized inthat said separate member is a pouring spout.

5. A closure assembly as set forth in claim 1, further characterized inthat said closure element is a closure plug having a flange-like topportion, said groove and said tongue being formed in said flange-liketop portion of said closure plug.

6. A closure assembly as set forth in claim 1, further characterized inthat said closure element is a closure plug, said groove and said tonguebeing formed in the lowermost portion of said closure plug.

7. A closure plug for use with a container closure assembly, said plughaving a flange-like portion in the outer surface wall thereof and acircumferential groove formed in said flange-like portion, said groovedefining with said wall an outwardly extending, at least slightlyresilient, sealing tongue, and a supporting ring formed of at leastslightly resilient material positioned in said groove.

8. A closure plug for use with a container closure assembly, said ,plughaving a circumferential groove formed in the outer surface wall of itslowermost portion, said groove defining with said wall an outwardlyextending, at least slightly resilient, sealing tongue, and a supportingring formed of at least slightly resilient material positioned in saidgroove.

9. A closure assembly as set forth in claim 1, further characterized inthat said outwardly extending sealing tongue in its inoperativecondition is inclined with respect to the sealing surface on thecooperating part of said closure assembly so that said tongue isdeformed and stressed when said closure element is applied.

10. A closure assembly as set forth in claim 1, further characterized inthat said surface on the cooperating closure part is provided with anannular ridge facing said sealing tongue.

11. A closure assembly as set forth in claim 1, further characterized inthat said sealing tongue is provided with an annular ridge on itssurface facing said sealing surface on the cooperating closure part.

12. A closure assembly as set forth in claim 10, further characterizedin that the diameter of the summit of said annular ridge is greater thanthe diameter of the circle defined by the axis of the cross-section ofsaid supporting ring.

13. A closure assembly as set forth in claim 11, further characterizedin that the diameter of the summit of said annular ridge is greater thanthe diameter of the circle defined by the axis of the cross-section ofsaid supporting ring.

14. A closure assembly as set forth in claim 1, further characterized inthat said closure element is a cap having an annular face depending fromthe top wall of the cap and snug-1y fitting in said orifice.

15. A closure assembly as set forth in claim 14, further characterizedin that said annular face is constituted by the circumferential wall ofa disc-shaped projection on the inner surface of the top wall of saidcap.

16. A closure assembly as set forth in claim 14, further characterizedin that said annular face is constituted by the circumferential wall ofan annular rib depending from the inner surface of the top wall of thecap.

17. A closure assembly as set forth in claim 14, further characterizedin that said annular face is constituted by the circumferential wall ofa recessed central portion of the top wall of the cap.

18. A closure assembly as set forth in claim 1, further characterized inthat said closure element is a plug having a circumferential dependingskirt portion surrounding the groove formed in said orifice definingportion.

References Cited by the Examiner FOREIGN PATENTS 812,090 4/59 GreatBritain.

THERON E. CONDON, Primary Examiner.

EARLE J. DRUMMOND, Examiner.

1. IN COMBINATION, A CLOSURE ASSEMBLY FOR A CONTAINER HAVIG AN ORIFICESURROUNDED BY AN ORIFICE DEFINING PORTION AND A CLOSURE ELEMENT FOR SAIDORIFICE, WHEREIN AT LEAST ONE OF SAID PORTION AND SAID ELEMENT HAS ACIRCUMFERENTIAL GROOVE FORMED IN ITS OUTER SURFACE WALL, SAID GROOVEDEFINING WITH SAID WALL AN ANNULAR, OUTWARDLY EXTENDING, AT LEASTSLIGHTLY RESILIENT TONGUE ADAPTED TO SEALINGLY ENGAGE A SURFACE ON THECOOPERATING PART OF THE CLOSURE ASSEMBLY, AND A SUPPORTING RING FORMEDOF SLIGHTLY RESILIENT MATERIAL POSITIONED IN SAID GROOVE.